[PATCH] crypto: caam/jr - update gcm detection logic

[Horia Geantă <horia.geanta@xxxxxxx>]

GCM detection logic has to change for two reasons:
-some CAAM instantiations with Era < 10, even though they have AES LP,
they now support GCM mode
-Era 10 upwards, there is a dedicated bit in AESA_VERSION[AESA_MISC]
field for GCM support

For Era 9 and earlier, all AES accelerator versions support GCM,
except for AES LP (CHAVID_LS[AESVID]=3) with revision CRNR[AESRN] < 8.

For Era 10 and later, bit 9 of the AESA_VERSION register should be used
to detect GCM support in AES accelerator.

Note: caam/qi and caam/qi2 are drivers for QI (Queue Interface), which
is used in DPAA-based SoCs; for now, we rely on CAAM having an AES HP
and this AES accelerator having support for GCM.

Signed-off-by: Horia Geantă <horia.geanta@xxxxxxx>
---
 drivers/crypto/caam/caamalg.c | 18 +++++++++++-------
 drivers/crypto/caam/regs.h    |  3 +++
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 579578498deb..72e978146061 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -3460,7 +3460,7 @@ static int __init caam_algapi_init(void)
 	u32 aes_vid, aes_inst, des_inst, md_vid, md_inst, ccha_inst, ptha_inst;
 	u32 arc4_inst;
 	unsigned int md_limit = SHA512_DIGEST_SIZE;
-	bool registered = false;
+	bool registered = false, gcm_support;
 
 	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
 	if (!dev_node) {
@@ -3493,7 +3493,7 @@ static int __init caam_algapi_init(void)
 	 * First, detect presence and attributes of DES, AES, and MD blocks.
 	 */
 	if (priv->era < 10) {
-		u32 cha_vid, cha_inst;
+		u32 cha_vid, cha_inst, aes_rn;
 
 		cha_vid = rd_reg32(&priv->ctrl->perfmon.cha_id_ls);
 		aes_vid = cha_vid & CHA_ID_LS_AES_MASK;
@@ -3508,6 +3508,10 @@ static int __init caam_algapi_init(void)
 			    CHA_ID_LS_ARC4_SHIFT;
 		ccha_inst = 0;
 		ptha_inst = 0;
+
+		aes_rn = rd_reg32(&priv->ctrl->perfmon.cha_rev_ls) &
+			 CHA_ID_LS_AES_MASK;
+		gcm_support = !(aes_vid == CHA_VER_VID_AES_LP && aes_rn < 8);
 	} else {
 		u32 aesa, mdha;
 
@@ -3523,6 +3527,8 @@ static int __init caam_algapi_init(void)
 		ccha_inst = rd_reg32(&priv->ctrl->vreg.ccha) & CHA_VER_NUM_MASK;
 		ptha_inst = rd_reg32(&priv->ctrl->vreg.ptha) & CHA_VER_NUM_MASK;
 		arc4_inst = rd_reg32(&priv->ctrl->vreg.afha) & CHA_VER_NUM_MASK;
+
+		gcm_support = aesa & CHA_VER_MISC_AES_GCM;
 	}
 
 	/* If MD is present, limit digest size based on LP256 */
@@ -3595,11 +3601,9 @@ static int __init caam_algapi_init(void)
 		if (c2_alg_sel == OP_ALG_ALGSEL_POLY1305 && !ptha_inst)
 			continue;
 
-		/*
-		 * Check support for AES algorithms not available
-		 * on LP devices.
-		 */
-		if (aes_vid  == CHA_VER_VID_AES_LP && alg_aai == OP_ALG_AAI_GCM)
+		/* Skip GCM algorithms if not supported by device */
+		if (c1_alg_sel == OP_ALG_ALGSEL_AES &&
+		    alg_aai == OP_ALG_AAI_GCM && !gcm_support)
 			continue;
 
 		/*
diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h
index 3cd0822ea819..8591914d5c51 100644
--- a/drivers/crypto/caam/regs.h
+++ b/drivers/crypto/caam/regs.h
@@ -253,6 +253,9 @@ struct version_regs {
 #define CHA_VER_VID_SHIFT	24
 #define CHA_VER_VID_MASK	(0xffull << CHA_VER_VID_SHIFT)
 
+/* CHA Miscellaneous Information - AESA_MISC specific */
+#define CHA_VER_MISC_AES_GCM	BIT(1 + CHA_VER_MISC_SHIFT)
+
 /*
  * caam_perfmon - Performance Monitor/Secure Memory Status/
  *                CAAM Global Status/Component Version IDs
-- 
2.17.1